Case IH F-1043-20 - ECU – Engine Control Unit (ECU / ECM) / A-095: 12V sensor supply 1 voltage is too high

The Electronic Control Unit (ECU) actively monitors its internal 12-volt sensor supplies. If the ECU determines that the voltage on sensor supply 1 has exceeded the maximum allowable threshold, it will trigger this fault.

• MAGNUM AFS Connect
• 240 Series Combines (7230, 8230, 9230, 6150)
• Puma Series Tractors
• Magnum Series Tractors
• Farmall Series Tractors (with CVT)
• Austoft 9900 Sugar Cane Harvesters

1. 1

   Check for external power: Verify that the machine battery has not been connected to an external power supply (such as a high-voltage jump starter or an external battery charger).

2. 2

   Verify fault status: Use the Case IH Electronic Service Tool (EST) to check if the fault is currently 'Active' or 'Inactive' (intermittent).

3. 3

   Inspect Connector X-917: Check Pin 84 at the ECU, which is associated with the 12V sensor supply 1.

4. 4

   Check electrical integrity: Test the wiring harness connected to Pin 84 for a short circuit to a high-voltage source (e.g., shorted to battery power) and check for correct voltage supply at the connected sensors.

1. 1

   Isolate the Power Supply

   Disconnect any external chargers or jump boxes. Turn the key off and let the ECU power down completely.

2. 2

   Test the Harness

   Disconnect connector X-917 from the A-095 ECU. Using a multimeter, probe Pin 84 and the associated sensor wiring to check for continuity to battery power (which would indicate a short to a high source).

3. 3

   Repair Wiring (If Applicable)

   If a short circuit is found in the harness between the ECU and the 12V sensors, locate the chafed or melted wire and repair the conductor.

4. 4

   Replace the ECU (If Wiring is Intact)

   If the wiring harness passes electrical integrity tests and the voltage is genuinely too high internally, the A-095 ECU has suffered an internal hardware failure. Replace ECM. Check wiring for correct voltage supply of the connected sensors.